This invention pertains to improvements in sliver high pile fabric knitting machines, of the type generally illustrated and described in U.S. Pat. Nos. 1,114,414, 2,680,360 and 3,010,297. More particularly, the invention is directed to an improvement in a multi-feed sliver high pile fabric circular knitting machine, whereby the productive capacity of such machine may be substantially increased.
Sliver high pile fabric circular knitting machines have been known since at least Oct. 20, 1914, the date of grant of J. C. Tauber U.S. Pat. No. 1,114,414. During the decades since the grant of that patent, the machines have been steadily improved as the result of numerous innovations, many of which have become the subject of patents. Such machines now are capable of knitting a wide range of patterned and multi-colored fabrics, due to various improvements in needle selecting mechanisms and sliver feeding control devices. In order to increase the productive capacity of such machines, the number of individual sliver and yarn feeding stations has been progressively increased. At the present time, it is conventional for such multi-feed machines to incorporate 8, 12, or even 14 separate sliver and yarn feeding stations. However, significant increases in the productive capacity of such machines have been difficult to achieve. Due to the nature and complexity of such machines, increasing their productive capacity by increasing the number of sliver and yarn feeding stations, or by increasing the speed of rotation of the needle cylinder, has met with limited success only.
A recent attempt to increase the productive capacity of a sliver high pile fabric knitting machine is illustrated in U.S. Pat. No. 3,886,767, issued June 3, 1975. In the machine of that patent, additional yarn feeds are incorporated intermediate the sliver and yarn feeding stations, to increase the number of fabric courses knit during each revolution of the needle cylinder. While the device of that patent has enhanced the productive capacity of the knitting machine, the additional courses knit per revolution of the cylinder are plain fabric courses, lacking pile fibers.
The primary object of this invention is to provide a new and useful improvement to a sliver high pile fabric circular knitting machine, in which the production of the machine is increased by increasing the number of pile fiber-retaining fabric courses knit per revolution of the needle cylinder at a sliver and yarn feeding station.
A further object of the invention is to provide, for a multi-feed sliver high pile fabric circular knitting machine, means for knitting a plurality of pile fabric courses at each sliver and yarn feeding station, during each revolution of the needle cylinder, comprising providing at each station a sliver feeding device for delivering a plurality of individual rovings to the needles, a separate yarn feed associated with each roving and a separate set of stitch cams associated with each roving.
A further object is to provide an improved method for increasing the production of a sliver high pile fabric knitting machine comprising the steps of providing, at one or more sliver and yarn feeding stations, a sliver feeding device adapted to deliver a plurality of spaced rovings of sliver fibers to arcuately spaced locations of the needle circle, providing at least two angularly spaced yarn feeds to feed yarn to the needles, each of said yarn feeds being associated with a separate roving, providing at least two angularly spaced sets of knitting cams, each set of cams being associated with a separate roving, and rotating the needles relative to, and actuating the needles at, each station to knit a plurality of pile fiber-retaining courses at each such station.
Other objects and advantages of this invention will be apparent from the following description of a preferred embodiment thereof, reference being had to the accompanying drawing.